A “battery” or battery pack may typically comprises some configuration of several battery cells. A battery cell typically includes a casing to hold the components the of the battery cell. The battery cell may include an anode (negative electrode) immersed in a suitable electrolyte. The anode may comprise any suitable compound such as porous carbon particles (e.g., graphite particles arranged into sheets), lithium metal, or a mix of activated carbon and titanium phosphate. The battery cell may further include a cathode immersed in an electrolyte. The cathode may comprise any suitable metal oxide compound such as cobalt-oxide (CoO2) particles, sodium iron phosphate particles, or lithium iron phosphate particles.
A battery discharges, for example, when it is connected across a load. During discharging, ions (e.g., lithium ions or sodium ions) flow through the electrolyte from the negative electrode to the positive electrode. Electrons flow from the negative electrode to the positive electrode through the load. The ions and electrons combine at the positive electrode. When no more ions flow for the given discharge potential applied across the cell, the battery can be deemed to be fully discharged.
During charging, the ions flow from the positive electrode to the negative electrode through the electrolyte. Electrons flow through the external charger in the direction from the positive electrode to the negative electrode. The electrons and ions combine at the negative electrode and deposit there. When no more ions flow for the given charge potential applied across the cell, the battery can be deemed fully charged and ready to use.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present disclosure.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.